It is important to know what rheumatoid factor is, before learning about its test. Rheumatoid factor is an antibody that is generally not present in the blood. Antibodies are found in blood and are normal protein important in the functioning of the immune system. In the cases where rheumatoid factor is measured in the blood, as an antibody it attaches or binds itself to other antibodies.
Rheumatoid Factor Test
It is a blood test ordered by the doctors to diagnose rheumatoid arthritis. It helps in distinguishing rheumatoid arthritis from the other forms of arthritis or any other diseases or conditions that might have similar symptoms to that of rheumatoid arthritis. As the rheumatoid arthritis is a connective tissue condition or disorder many times the signs and the symptoms of the patient cannot be readily identified, in such cases rheumatoid factor (RF) test is an important tool in diagnosis.
It is estimated that about 80% of the adult have rheumatoid factor present in their blood but very few children suffer from rheumatoid arthritis.
When to have Rheumatoid Factor Test
Doctor orders the patient to have the rheumatoid factor test done when there are rheumatoid arthritis symptoms like swelling, warmth, stiffness and pain in the joints. Also forming of nodules under the skin, and when an X-ray is done which shows the loss of bone and cartiledge and also swelling of the joint capsules.
Presence of Rheumatoid Factor
It is not only patients with rheumatoid arthritis in whose blood the rheumatoid factor can be found, people suffering from other conditions can show traces of rheumatoid factor too. People suffering from infectious disease like hepatitis, tuberculosis, infectious mononucleosis, syphilis will have the rheumatoid factor present in their blood. Patients with connective tissue diseases like systemic lupus erythematosus will have positive in the rheumatoid factor test. At times people without any of these diseases can test positive and it is likely to happen who have a family history of rheumatoid arthritis.
At times even after tests the rheumatoid factor can be negative or very low in a patient, often it happens that with age the test value increases.
Significance of Rheumatoid Factor in Rheumatoid Arthritis
People who are diagnosed with high level of rheumatoid factor are generally associated with chronic rheumatoid diseases. It can also be an indication that the person is likely to develop other kinds of rheumatoid diseases that are non-joint ailments like rheumatoid lung disease or rheumatoid nodules.